| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 6.1 | 6.78 | 4.92 |
| 2024 | 3.77 | 8.78 | 1.95 |
| 2023 | 3 | 3.94 | 2.42 |
| 2022 | 3.61 | 4.8 | 2.61 |
| 2021 | 4.81 | 7.98 | 3.14 |
| 2020 | 4.01 | 5.55 | 3.09 |
| 2019 | 3.78 | 4.65 | 2.76 |
| 2018 | 3.67 | 5.93 | 2.22 |
| 2017 | 4.58 | 6.25 | 3.42 |
| 2016 | 5.65 | 7.09 | 4.45 |
| 2015 | 7.37 | 14.55 | 3.94 |
| 2014 | 3.82 | 4.47 | 3.06 |
| 2013 | 2.35 | 3.93 | 1.67 |
| 2012 | 2.2 | 2.86 | 1.55 |
| 2011 | 2.76 | 3.49 | 1.75 |
| 2010 | 3.24 | 3.88 | 2.51 |
| 2009 | 2.27 | 3.11 | 1.21 |
| 2008 | 2.03 | 3.62 | 0.98 |
| 2007 | 2.94 | 4.27 | 1.88 |
| 2006 | 1.94 | 2.18 | 1.76 |
| 2005 | 2.39 | 3.37 | 1.72 |
| 2004 | 4 | 6.16 | 2.88 |
| 2003 | 4.33 | 5.34 | 2.85 |
| 2002 | 6.24 | 6.95 | 5.5 |
| 2001 | 7.66 | 9.69 | 5.77 |
| 2000 | 9.32 | 10.77 | 7.64 |
| 1999 | 7.46 | 11.91 | 4.33 |